Consumers often desire skin lightening products that are affordable, safe, stable, and can produce consumer-noticeable skin lightening after routine use. In this regard, consumers may desire skin lightening products to either lighten the color of their skin and/or minimize skin spots or blotchiness. For example, consumers may desire skin lightening agents to counteract fluctuations in skin color brought about by hormonal fluctuations or environmental stressors like UV light.
At least some skin lightening agents work by targeting or influencing one or more of the steps involved in the development of skin color. Human skin color is attributed in part to the outermost layer of skin (i.e. epidermis) where many melanocytes may be located. The synthesis of melanin, pigments that may be dark brown/black or light red-yellow, is a complex process that involves the enzyme, tyrosinase, and can take place within the melanosomes of the melanocytes. These melanosomes may be transferred from the melanocyte to the keratinocytes.
It has been discovered that combining different skin lightening agents, for example—combining vitamin B3 with N-undecylenoyl-L-phenylalanine, can increase their effectiveness. However, combining ingredients may also result in undesirable side-effects, such as increased irritation and/or erythema, on certain skin-types dependent, for example, on the conditions in which the topical composition is applied. Consumers experiencing a level of discomfort and/or irritability upon using a cosmetic composition including skin lightening products may choose not to repurchase said cosmetic composition. Thus, there exists a need to find a solution to reduce negative effects, such as irritation, while maintaining an acceptable level of efficacy of skin lightening.